Owing to the progress in various technological fields, integrated circuit (IC) cards, such as credit cards, cash cards, phone cards, stored-value cards and the like, have been used in many transactions as means of payment. According to the data access and data reading interfaces thereof, the currently available IC cards can be generally classified into three types, namely, IC cards with a contact type interface, IC cards with a non-contact type interface, and IC cards with a hybrid-type interface.
An IC card with a contact type interface, such as a general cash card, enables data access via metal contacts. An IC card with a non-contact interface, such as a stored-value card or electronic wallet often used for mass transit, enables data access via a sensor. Since various kinds of cards have been introduced into the market, the IC card with a hybrid-type interface is developed to integrate the functions of credit card, cash card, electronic wallet, stored-value card and the like into one single IC card, allowing a user to get diversified services with only one card.
Conventional electronic smart cards have not a display function, and a card holder can know the data stored in the card, such as the balance, only via printed bills or a card reader. To overcome this disadvantage, an IC card with display has been developed to allow a user to look up the data stored in the card in real time.
FIG. 1 is a block diagram of a first conventional IC card with display. As shown, the first conventional IC card includes a display 10, a communication interface 11, a microprocessor 12, a display driving circuit 13, a boost circuit 14, a rectifying regulator circuit 15, and a non-volatile readable memory 16. The microprocessor 12, after receiving a signal from the communication interface 11, can store data in the non-volatile readable memory 16, and the display driving circuit 13 converts the data into a driving signal of the display 10. Meanwhile, the boost circuit 14 converts a direct current (DC) power generated by the rectifying regulator circuit 15 into a driving voltage of the display 10, so that a user can look up data directly on the display 10. In addition, the microprocessor 12 can also transmit a response signal to an external card reader through the communication interface 11.
The conventional communication interface 11 is a combination of a non-contact type radio frequency (RF) smart card IC 17 and a contact type smart card IC 18. The IC card obtains required driving power from the non-contact type RF smart card IC 17 or the contact type smart card IC 18.
The non-contact type RF smart card IC 17 is internally provided with an antenna 19, which receives an RF signal generated by an external card reader. The communication interface 11 performs RF demodulation for the coupled signal. On the other hand, the coupled signal passes the rectifying regulator circuit 15 to generate a DC power for supplying an internally needed voltage of the IC card. The contact type smart card IC 18 receives a digital serial signal from an external card reader and decodes the received digital serial signal for reading by the microprocessor 12. The external card reader also provides via the contact type smart card IC 18 a DC power for use by all internal circuits of the IC card.
Since the first conventional IC card does not include any power generator, it must rely on an induced current generated by the received external signal. The induced current is supplied to the boost circuit 14 and the rectifying regulator circuit 15 to enable data communication and data display. The user could not get the data in the IC card without a card reader, so that the first conventional display-enabled card is not so convenient in use.
A second conventional IC card as shown in FIG. 2 has been developed and introduced into the market in an attempt to overcome the disadvantages of the above-mentioned first conventional IC card. Please refer to FIG. 2. The second conventional IC card includes a flexible display 20, a display circuit 21, a communication interface 22, a smart card IC 23, and a power generator 24. The display circuit 21 is connected to the flexible display 20; and the communication interface 22 is connected to the display circuit 21 via the smart card IC 23. The smart card IC 23 performs a security authentication, so that data communication between the communication interface 22 and the display circuit 21 via the smart card IC 23 is allowed only when the security authentication succeeds.
The display circuit 21 includes a display driver 211 for driving the flexible display 20 and a display controller 212 for controlling the display driver 211. The display driver 211 is connected to the flexible display 20 while the display controller 212 is connected to the display driver 211 and the smart card IC 23. In addition, the smart card IC 23 includes a security module 231 and a storage unit 232. The security module 231 performs the security authentication to protect the IC card against a hacker; and data stored in the storage unit 232 can be accessed only when the security authentication succeeds. Further, the power generator 24 is connected to the display circuit 21, the communication interface 22 and the smart card IC 23 to supply the IC card with required working voltage via the RF signal received by the communication interface 22.
In the second conventional IC card, it is the RF signal received by the communication interface that drives the power generator in the IC card to generate the required working voltage. That is, according to the second conventional IC card, an external card reader is still needed for generating the required working voltage to enable data display, and a user just could not get data stored in the IC card without an external card reader. Moreover, the working voltage supplied by the built-in power generator is often unstable to result in poor sensing ability or poor data communication. It is therefore necessary to work out an improved display-enabled flexible IC card in order to overcome the above disadvantages of the conventional IC cards with display.